A former boy scout who exposed gaping security flaws within Perth's Police headquarters by impersonating an officer over several weeks earlier this year was only trying to serve his community, a court has heard.

A Perth magistrate has sentenced 18-year-old Christopher Bergroth to a 15-month community based order, involving 100 hours of community service and more than $2000 in fines and costs.

Bergroth had pleaded guilty to 38 charges which included stealing police uniforms and equipment, impersonating an officer, stealing petrol using a police fleet card, and fraud.

He was originally swiped into Perth Police Headquarters by a friend who worked as an auxiliary for WA Police on April 21, 2012, the Perth Magistrate's Court heard at his sentencing on Monday.

Advertisement

Bergroth stole enough pieces of uniform from disposal bins at the station to pass himself off as a police officer over the following six weeks.

During his time in uniform the teenager attended a crash scene, questioning witnesses and handing their statements over to legitimate officers at the scene.

He also attended several police stations, taking orders from senior officers and performing general duties, such as taking prisoners their meals, the court heard.

Bergroth was finally questioned by officers at the Perth Watch House, while "undertaking duties" on June 1 and admitted to being a civilian.

Over the course of a five hour police interview Bergroth then told the police the full details of his long-running rouse.

No charges were brought against the friend who initially let Bergroth into the watch house to steal the uniforms, but the man has resigned from his position, the court heard.

Defence lawyer Michael Clarke said a foot injury had prevented Bergroth from trying out as a police recruit, prompting the "unusual" turn in his behaviour.

"Since he was a young boy Mr Bergroth formed a lifelong ambition to become a police officer," Mr Clarke told the court.

He said once senior police officers started giving Bergroth orders, under the false belief he was a cop, the teenager was caught on a "slippery slope".

"It clearly got out of hand very quickly," Mr Clarke said.

"He was a scout wanting to help out and meet a lifelong ambition."

But the court also heard Bergroth had stolen a fuel card from a police fleet car to fill his personal car up on two occasions.

He was also pulled over by police for speeding at one stage and identified himself as an officer on urgent business to avoid a fine, the court heard.

State prosecutor Brent Meertens speaking outside court said police had tightened security following the debacle.

"We've now become increasingly aware of someone perhaps impersonating a police officer," he said.

"Everyone's been instructed to be more careful and even to challenge people within the system."

Prosecutors had not pushed for jail.

Mr Meertens said he believed Bergroth had just genuinely wanted to be an officer.

"This was his way of living out that dream," he said.

He conceded a "worrying" "public perception" about police security had come out of the incident, but he said "things have tightened up a lot," since.

Bergroth was described by those close to him as a "kind, caring, benevolent sort of fellow," Mr Clarke told the court.

Although his hopes of becoming a police officer had been "dashed", Mr Clarke said his client was now hoping to join the Australian Defence Force, and "serve his community".

Accompanied by an uncle at court today Bergroth thanked his lawyer and family for their support.